1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <linux/export.h>
  4#include <linux/ioport.h>
  5#include <linux/screen_info.h>
  6#include <linux/string.h>
  7
  8static void resource_init_named(struct resource *r,
  9				resource_size_t start, resource_size_t size,
 10				const char *name, unsigned int flags)
 11{
 12	memset(r, 0, sizeof(*r));
 13
 14	r->start = start;
 15	r->end = start + size - 1;
 16	r->name = name;
 17	r->flags = flags;
 18}
 19
 20static void resource_init_io_named(struct resource *r,
 21				   resource_size_t start, resource_size_t size,
 22				   const char *name)
 23{
 24	resource_init_named(r, start, size, name, IORESOURCE_IO);
 25}
 26
 27static void resource_init_mem_named(struct resource *r,
 28				   resource_size_t start, resource_size_t size,
 29				   const char *name)
 30{
 31	resource_init_named(r, start, size, name, IORESOURCE_MEM);
 32}
 33
 34static inline bool __screen_info_has_ega_gfx(unsigned int mode)
 35{
 36	switch (mode) {
 37	case 0x0d:	/* 320x200-4 */
 38	case 0x0e:	/* 640x200-4 */
 39	case 0x0f:	/* 640x350-1 */
 40	case 0x10:	/* 640x350-4 */
 41		return true;
 42	default:
 43		return false;
 44	}
 45}
 46
 47static inline bool __screen_info_has_vga_gfx(unsigned int mode)
 48{
 49	switch (mode) {
 50	case 0x10:	/* 640x480-1 */
 51	case 0x12:	/* 640x480-4 */
 52	case 0x13:	/* 320-200-8 */
 53	case 0x6a:	/* 800x600-4 (VESA) */
 54		return true;
 55	default:
 56		return __screen_info_has_ega_gfx(mode);
 57	}
 58}
 59
 60/**
 61 * screen_info_resources() - Get resources from screen_info structure
 62 * @si: the screen_info
 63 * @r: pointer to an array of resource structures
 64 * @num: number of elements in @r:
 65 *
 66 * Returns:
 67 * The number of resources stored in @r on success, or a negative errno code otherwise.
 68 *
 69 * A call to screen_info_resources() returns the resources consumed by the
 70 * screen_info's device or framebuffer. The result is stored in the caller-supplied
 71 * array @r with up to @num elements. The function returns the number of
 72 * initialized elements.
 73 */
 74ssize_t screen_info_resources(const struct screen_info *si, struct resource *r, size_t num)
 75{
 76	struct resource *pos = r;
 77	unsigned int type = screen_info_video_type(si);
 78	u64 base, size;
 79
 80	switch (type) {
 81	case VIDEO_TYPE_MDA:
 82		if (num > 0)
 83			resource_init_io_named(pos++, 0x3b0, 12, "mda");
 84		if (num > 1)
 85			resource_init_io_named(pos++, 0x3bf, 0x01, "mda");
 86		if (num > 2)
 87			resource_init_mem_named(pos++, 0xb0000, 0x2000, "mda");
 88		break;
 89	case VIDEO_TYPE_CGA:
 90		if (num > 0)
 91			resource_init_io_named(pos++, 0x3d4, 0x02, "cga");
 92		if (num > 1)
 93			resource_init_mem_named(pos++, 0xb8000, 0x2000, "cga");
 94		break;
 95	case VIDEO_TYPE_EGAM:
 96		if (num > 0)
 97			resource_init_io_named(pos++, 0x3bf, 0x10, "ega");
 98		if (num > 1)
 99			resource_init_mem_named(pos++, 0xb0000, 0x8000, "ega");
100		break;
101	case VIDEO_TYPE_EGAC:
102		if (num > 0)
103			resource_init_io_named(pos++, 0x3c0, 0x20, "ega");
104		if (num > 1) {
105			if (__screen_info_has_ega_gfx(si->orig_video_mode))
106				resource_init_mem_named(pos++, 0xa0000, 0x10000, "ega");
107			else
108				resource_init_mem_named(pos++, 0xb8000, 0x8000, "ega");
109		}
110		break;
111	case VIDEO_TYPE_VGAC:
112		if (num > 0)
113			resource_init_io_named(pos++, 0x3c0, 0x20, "vga+");
114		if (num > 1) {
115			if (__screen_info_has_vga_gfx(si->orig_video_mode))
116				resource_init_mem_named(pos++, 0xa0000, 0x10000, "vga+");
117			else
118				resource_init_mem_named(pos++, 0xb8000, 0x8000, "vga+");
119		}
120		break;
121	case VIDEO_TYPE_VLFB:
122	case VIDEO_TYPE_EFI:
123		base = __screen_info_lfb_base(si);
124		if (!base)
125			break;
126		size = __screen_info_lfb_size(si, type);
127		if (!size)
128			break;
129		if (num > 0)
130			resource_init_mem_named(pos++, base, size, "lfb");
131		break;
132	case VIDEO_TYPE_PICA_S3:
133	case VIDEO_TYPE_MIPS_G364:
134	case VIDEO_TYPE_SGI:
135	case VIDEO_TYPE_TGAC:
136	case VIDEO_TYPE_SUN:
137	case VIDEO_TYPE_SUNPCI:
138	case VIDEO_TYPE_PMAC:
139	default:
140		/* not supported */
141		return -EINVAL;
142	}
143
144	return pos - r;
145}
146EXPORT_SYMBOL(screen_info_resources);